This would apparently cause other problems: > Interesting enough, waifu2x performed very poorly on anime. A plausible explaination is that the network was simp

This would apparently cause other problems: > Interesting enough, waifu2x performed very poorly on anime. A plausible explaination is that the network was simply not trained to upscale these types of images. Usually anime style art have sharper lines and contain much more small details/textures compared to anime. The distribution of images used to train waifu2x must have been mostly art images from sites like DevianArt/Danbooru/Pixiv, and not anime.